Review Article

Statistical Analysis of Efficient Unbalanced Factorial Designs for Two-Color Microarray Experiments

Figure 3

SAS code for classical ANOVA and EGLS inference. Comments describing purpose immediately provided after corresponding code between /* and */ as with a regular SAS program. EGLS based on REML would simply involve substituting method = reml for method = type3 in the third line of the code.
title “Mixed model analysis of log fluorescence intensity data from gene 30”;
proc mixed
  data=gene30 /* name of data as provided in Table 4*/
  method = type3;
  /* Provides classical ANOVA table and EGLS based on ANOVA estimates of VC */
  /* If REML estimates of VC are desired, change above line to method = reml; */
  where ((array <= 9) or (15 <=array <= 23));
   /* Using A-loop component (arrays 1-9, 15-23) of Table 4 data only */
  class rep array inoc time dye;
   /* name of fixed and random classification factors in design */
  model ly = inoc time inoc*time dye
   /* Specify response variable and fixed effects here */
   /ddfm = kr
   /* Use Kenward-Roger's procedure to estimate denominator degrees of freedom */
    e3;
   /* e3 will print the contrast matrices KA, KB and KAB (see (A.8), (A.9) and
    (A.10) of Appendix 5) used to provide the EGLS ANOVA F-test statistics (optional) */
  random array(time) rep(inoc*time) ; /* Specify random effects */
  estimate “k1 contrast”
    int 0 inoc 1 1 0 time 0 00 inoc*time 1 00 1 00 00 0 dye 0 0;
   /* contrast coefficients as specified for k1 in (A.6) of Appendix 5*/
  estimate “k2 contrast”
   int 0 inoc 0 00 time 1 1 0 inoc*time 1 1 00 00 00 0 dye 0 0;
   /* contrast coefficients as specified for k2 in (A.7) of Appendix 5*/
run;